Oxygen adsorption on clean (100), (110) and (111) surfaces was studied by means of UPS, XPS and LEED. The results on oxygen adsorption were explained on the basis of the structures and electronic states on the clean (100), (110) and (111) surfaces. The surface states on (110) disappeared at an oxygen exposure of 0.4L where a c(2 x 2) LEED pattern disappeared and a (1 x 1) LEED pattern appeared. The work function on (110) was increased to ∼3.8eV by an oxygen exposure of ∼2L. The surface states on (111) disappeared at an oxygen exposure of ∼2 L where the work function had a maximum value of ∼4.4 eV. Oxygen was adsorbed on the surface boron atoms of (111) up to an exposure of ∼2L. Above this exposure, oxygen was adsorbed on another site to lower the work function from ∼4.4 to ∼3.8eV up to an oxygen exposure of ∼100L. The initial sticking coefficient on (110) had the highest value of ∼1 among the (100), (110) and (111) surfaces. The (100) surface was most stable to oxygen among these surfaces. It was suggested that the dangling bonds of boron atoms played an important role in oxygen adsorption on the LaB6 surfaces.

Oxygen Adsorption on the LaB6(100), (110) and (111) Surfaces. Nishitani, R., Oshima, C., Aono, M., Tanaka, T., Kawai, S., Iwasaki, H., Nakamura, S.: Surface Science, 1982, 115[1], 48-60